This application relates generally to medical and surgical equipment and, more particularly, to a new and improved apparatus for expanding medical or other resilient tubing.
Flexible tubing plays an important role in many industries, such as the medical field, where a conduit must be provided to transport fluids from one depot to another. Various materials have been developed for use in molding flexible, durable, and inexpensive tubing. By connecting such tubing to diverse ends and connectors, e.g. fluid containers, Y-sites, and hypodermic needles, a vast array of different systems may be readily assembled.
In order to provide an effective fluid conduit system, it is imperative that the coupling between the tubing and the mating portions of the fittings form a tight seal. In the medical field, e.g., hospitals and doctor's offices, leakage between the fittings and the tubing is especially critical since it may introduce air bubbles into the conduits, contaminating or interrupting the flow of fluid therein. Moreover, passing bubbles into the patient's bloodstream may cause emboli formation. To remedy this, a number of male-type fittings, e.g. tapered, ribbed or stepped connectors, have been developed to maintain an air-tight connection with flexible tubing. These fittings require that the tubing be threaded over or tightly received by "male" portion of the fitting. While it is possible to axially or longitudinally force the tubing over this male portion, such methodology may kink the tubing, expediting the tubing's failure, or fail to insert the fitting a sufficient distance into the tubing end to effect the required seal.
Various expander devices for insertion into and/or expansion of a collapsed tubular member from within have been known for a number of years, and by way of example, several forms of such devices can be found in U.S. Pat. Nos. 4,494,398; 3,749,365; 4,475,373; or 4,155,242.
In addition, certain tools have been developed to expand medical tubing so that the fitting can be inserted. Various medical tubing expanders include, by way of example, hand-held pliers-type devices. These latter devices generally require manual gripping by the operator. This prevents the operator from using both hands to immediately grasp and insert the fitting within the expanded tubing. Since resilient tubing begins to return to its unexpanded dimensions almost immediately after being stretched, this manual gripping reduces the effectiveness of the conventional medical tubing expanders.
Moreover, such tools typically have jaws which pivot outward relative to each other to expand the tubing. As a result, the tubing's degree of flair and rate of expansion may be adversely affected. Thus, unusually sized or resilient tubing may be subject to over-stretching or splitting. Furthermore, these devices may apply the expansive stress to small portions of the tubing, causing localized material fatigue and expediting tubing failure. Because different materials vary in the optimum stretch rate, such tools may not accommodate diverse materials. As a result, conventional medical tubing expander tools have not completely resolved the needs for gradual and adjustable expansion of resilient tubing, and further have not completely resolved the need to quickly insert the fitting into the expanded tubing.
There exists, therefore, a significant long-felt need for an improved medical tubing expander assembly for expanding a variety of medical tubing types, wherein the assembly gradually and adjustably expands resilient tubing, and further wherein the expander assembly is remotely actuable.